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  <title>设定文件的访问和修改时间</title>
 </head>
 <body class="docs"><div id="layout">
  <div id="layout-content"><div id="function.touch" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">touch</h1>
  <p class="verinfo">(PHP 4, PHP 5, PHP 7)</p><p class="refpurpose"><span class="refname">touch</span> &mdash; <span class="dc-title">设定文件的访问和修改时间</span></p>

 </div>
 <div class="refsect1 description" id="refsect1-function.touch-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>touch</strong></span>
    ( <span class="methodparam"><span class="type">string</span> <code class="parameter">$filename</code></span>
   [, <span class="methodparam"><span class="type">int</span> <code class="parameter">$time</code><span class="initializer"> = time()</span></span>
   [, <span class="methodparam"><span class="type">int</span> <code class="parameter">$atime</code></span>
  ]] ) : <span class="type">bool</span></div>

  <p class="para rdfs-comment">
   尝试将由 <code class="parameter">filename</code>
   给出的文件的访问和修改时间设定为给出的 <code class="parameter">time</code>。
   注意访问时间总是会被修改的，不论有几个参数。
  </p>
  <p class="para">
   如果文件不存在，则会被创建。
  </p>
 </div>


 <div class="refsect1 parameters" id="refsect1-function.touch-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>

    
     <dt>
<code class="parameter">filename</code></dt>

     <dd>

      <p class="para">
       要设定的文件名。
      </p>
     </dd>

    
    
     <dt>
<code class="parameter">time</code></dt>

     <dd>

      <p class="para">
       要设定的时间。如果没有提供参数 <code class="parameter">time</code> 则会使用当前系统的时间。
      </p>
     </dd>

    
    
     <dt>
<code class="parameter">atime</code></dt>

     <dd>

      <p class="para">
       如果给出了这个参数，则给定文件的访问时间会被设为
   <code class="parameter">atime</code>，否则会设置 为<code class="parameter">time</code>。如果没有给出这两个参数，则使用当前系统时间。
      </p>
     </dd>

    
   </dl>

  </p>
 </div>

 
 <div class="refsect1 returnvalues" id="refsect1-function.touch-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">
   成功时返回 <strong><code>TRUE</code></strong>， 或者在失败时返回 <strong><code>FALSE</code></strong>。
  </p>
 </div>


 <div class="refsect1 changelog" id="refsect1-function.touch-changelog">
  <h3 class="title">更新日志</h3>
  <p class="para">
   <table class="doctable informaltable">
    
     <thead>
      <tr>
       <th>版本</th>
       <th>说明</th>
      </tr>

     </thead>

     <tbody class="tbody">
      <tr>
       <td>5.3.0</td>
       <td>
        能够修改 Windows 下目录的最后修改时间。
       </td>
      </tr>

     </tbody>
    
   </table>

  </p>
 </div>


 <div class="refsect1 examples" id="refsect1-function.touch-examples">
  <h3 class="title">范例</h3>
  <p class="para">
   <div class="example" id="example-2849">
    <p><strong>Example #1 <span class="function"><strong>touch()</strong></span> 例子</strong></p>
    <div class="example-contents">
<div class="phpcode"><pre><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #007700">if&nbsp;(</span><span style="color: #0000BB">touch</span><span style="color: #007700">(</span><span style="color: #0000BB">$filename</span><span style="color: #007700">))&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #0000BB">$filename&nbsp;</span><span style="color: #007700">.&nbsp;</span><span style="color: #DD0000">'&nbsp;modification&nbsp;time&nbsp;has&nbsp;been&nbsp;changed&nbsp;to&nbsp;present&nbsp;time'</span><span style="color: #007700">;<br />}&nbsp;else&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">'Sorry,&nbsp;could&nbsp;not&nbsp;change&nbsp;modification&nbsp;time&nbsp;of&nbsp;'&nbsp;</span><span style="color: #007700">.&nbsp;</span><span style="color: #0000BB">$filename</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</pre></div>
    </div>

   </div>
  </p>
  <p class="para">
   <div class="example" id="example-2850">
    <p><strong>Example #2 使用 <code class="parameter">time</code> 参数的 <span class="function"><strong>touch()</strong></span></strong></p>
    <div class="example-contents">
<div class="phpcode"><pre><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br /></span><span style="color: #FF8000">//&nbsp;This&nbsp;is&nbsp;the&nbsp;touch&nbsp;time,&nbsp;we'll&nbsp;set&nbsp;it&nbsp;to&nbsp;one&nbsp;hour&nbsp;in&nbsp;the&nbsp;past.<br /></span><span style="color: #0000BB">$time&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">time</span><span style="color: #007700">()&nbsp;-&nbsp;</span><span style="color: #0000BB">3600</span><span style="color: #007700">;<br /><br /></span><span style="color: #FF8000">//&nbsp;Touch&nbsp;the&nbsp;file<br /></span><span style="color: #007700">if&nbsp;(!</span><span style="color: #0000BB">touch</span><span style="color: #007700">(</span><span style="color: #DD0000">'some_file.txt'</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">$time</span><span style="color: #007700">))&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">'Whoops,&nbsp;something&nbsp;went&nbsp;wrong...'</span><span style="color: #007700">;<br />}&nbsp;else&nbsp;{<br />&nbsp;&nbsp;&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">'Touched&nbsp;file&nbsp;with&nbsp;success'</span><span style="color: #007700">;<br />}<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</pre></div>
    </div>

   </div>
  </p>
 </div>


 <div class="refsect1 notes" id="refsect1-function.touch-notes">
  <h3 class="title">注释</h3>
  <blockquote class="note"><p><strong class="note">Note</strong>: <p class="para">注意：不同文件系统对时间的判断方法可能是不相同的。</p></p></blockquote>
  <div class="warning"><strong class="warning">Warning</strong>
   <p class="para">
    在 PHP 5.3.0 之前无法修改 Windows 下目录的最后修改时间。
   </p>
  </div>
 </div>

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